Mechanism for retarding the backing thread carrier of a straight-bar knitting machine



Sept. 2, 1956 s. A. MONK 2,764,007

MECHANISM FOR RETARDING THE BACKING THREAD CARRIER OF A STRAIGHT-BAR KNITTING MACHINE Filed Feb 14, 1955 w AMEN w W k INVENTOR. aA/m-z MR /m flM/m' Samuel Arthur Monk, Sutton-in-Ashfield, England Application February 14, 1955, Serial No. 488,043

Claims priority, application Great Britain February 17, 1954 Claims. (Cl. 66-126) The present invention relates to improvements in straight-bar knitting machines provided with a facing thread carrier and with a backing thread carrier. More particularly, it relates to an improved mechanism for straight-bar knitting machines of the class described whereby the facing thread is given a lead over the backing thread in both directions of traverse and whereby the facing thread is always laid on the front or face of the work.

Straight-bar knitting machines are known wherein the thread carrier bar is connected to a driving member which is reciprocated by a flexible member such as a chain or chains, these latter being mounted on sprockets in well known manner so that the traversing movement of the driving member may be altered from time to time to shape an article produced on the machine.

The chain or chains pass about sprockets at each end and the sprockets at one end are secured to an axle carried by fixed bearings. In order to drive the chain, the axle has a pinion secured thereto which meshes with a pinion on aonther axle, which axle is rotated about its axis first in one direction and then in the other direction by a second pinion disposed on the axle and engaging with a toothed rack which is reciprocated by the draw lever of the machine.

In U. S. application Serial Number 484,765, filed January 28, 1955, by Dennis Matthews, driving means for the thread carrier bar of such a straight-bar knitting machine are described wherein conventional knitting work may be produced in simple and certain manner.

In order to produce plated work on a straight-bar knitting machine, a facing thread carrier and a backing thread carrier are required. For the facing thread to appear on the front or face of the work the facing thread carrier must be given an appropriate lead over the backing thread carrier as they traverse to lay their threads.

It is an object of the present invention to provide flexible driving means for the facing thread carrier and the backing thread carrier.

Another object of the present invention is to provide driving means for the thread carriers which will ensure that the facing thread carrier leads the backing thread carrier by a suitable amount to ensure proper positioning of the facing thread carrier.

A further object of the invention is to provide driving means for the facing and backing thread carriers of a straight-bar knitting machine, said driving means ensuring appropriate lead of the facing thread carrier over the backing thread carrier irrespective of the direction of traverse of the carriers.

In accordance with the present invention, the facing thread carrier bar is driven by a flexible member operated in the normal manner from a reciprocating rack and the backing thread carrier bar is driven by a second flexible member which is reciprocated together with the first mentioned flexible member by means permitting the first mentioned flexible member to start moving a predeter States Patent 0 mined interval in advance of the second flexible member each time they change direction. Consequently, the facing thread carrier bar maintains a predetermined lead over the backing thread carrier bar in either direction of traverse.

The second flexible member may be driven from a reciprocating rack by suitable gearing incorporating a dog clutch having a predetermined amount of clearance between the dogs to provide lost motion each time the gearing reverses. The dog clutch may conveniently be associated with the axle which carries the sprockets about which the flexible member or chain passes at one end, and by a suitable disposition of the chains both carrier bars may be driven by the same reciprocating rack.

The invention will now be more particularly described with reference to the accompanying drawing wherein:

Fig. 1 is a front elevation of facing thread and backing thread carrier driving mechanism for a straight-bar knitting machine constructed in accordance with the present invention;

Fig. 2 is a section taken along line II-ll of Fig. 1 showing the dog drive for the backing thread carrier driving mechanism;

Fig. 3 is a section through the dog drive taken along line III--III of Fig. 2 and showing the clearance between the dogs; and

Fig. 4 is a diagrammatic view of the position of the facing thread carrier and backing thread carrier in each division of the machine during the laying of a course on the needles of the machine.

In the drawing, wherein like reference characters indicate like parts, Figs. 2 and 3 are drawn to a slightly larger scale than Fig. 1.

Referring now more particularly to the drawing, in Fig. 1 there is shown a flexible member such as a chain 10 for driving the facing thread carrier bar (not shown) which in turn drives the facing thread carrier 11 (Fig. 4-). The chain 10 may conveniently be endless and may comprise two parallel chains trained over a pair of sprockets 12 at one end, the sprockets 12 being mounted on an axle 13 carried by a fixed bracket 14. The chains 10 also pass about sprockets arranged on movable saddles 15, 16, so that a driver 17 on the chain can move into and out of the space between two arms (not shown) on a sliding member to reciprocate the latter as the chain is driven first in one direction and then in the other. The sliding member ordriven member is connected to the facing thread carrier bar by means of a releasable bolt so that it can be disengaged therefrom when desired, the arrangement being more fully described in U. S. Application Serial Number 484,765. The position of the saddles 15, 16 can be adjusted from time to time to alter the traverse of the driven member and consequently that of the facing thread carriers for shaping the work produced on the machine.

The backing thread carrier bar is driven by a second flexible member which may conveniently comprise two parallel endless chains 18. These chains 18 pass about end sprockets 19 on an axle 20 carried by the fixed bracket 14 and further pass about suitably disposed sprockets on saddles 21, 22, associated with the plating thread carrier bar driving chain and moved in unison with the saddles 15, 16. Consequently, the facing thread carrier and the ground thread carrier traverse the same distance.

The chains 18 carry a further driver 23 to reciprocate another driven member (not shown) which latter actuates the backing thread carrier bar in the same manner described with reference to the actuation of the facing thread carrier bar.

In order that the facing thread carrier 11 leads the backing-thread carrier-24 (Fig. 4), the two driving chains 10. and .18, are arrangedso that at the. start of each thr ad.

laying motion the facing thread carrier driving chain moves a predetermined-distance before the backing thread carrier driving chain 18.;startstofmove, thalatter being retarded. i

In order to effect this result the following arrangement may be adopted. The axle 13 of I the sprockets 12;; at the left hand end of the facing thread carrier driving chain 10' has a pinion 25'secured thereto which. meshes with a driving pinion 26 on an axle 27, the latter having a second pinion gear 28' thereon. The second pinion gear 28 engages with a rack 29 reciprocated longitudinally by a connection with the draw lever 30 of the machine.

The right hand end sprockets 1 9.of the backing thread carrier driving chain 18'are disposed so that a pinion 31, coaxial with the sprocket axle20,-meshes with the driving pinion 26 previouslymentioned. The pinion .31.is connectedto the sprocket axle 20 by a dog clutch32 in which apredeterrnined amount, of .clearanced ,(Fig, 3) is provided between the dogs.

As a result when the direction of movement-of the chains 10, 18 is reversed the drivingnmember of thedog clutch 32 first takes up the clearance a between thedogs before it starts to drive the sprockets 19-andconsequently the chain 18.. Thus the driving chain 10 .for the facing thread carrier 11 always starts to move before theothpr chain 18 so that the facing thread carrier 11 always maintains a lead over the backing threadcarrier 24.

If it is desired to produce a V neck front for a, garment in plated fabric the facing thread carrier bar driving chain it passes about sprockets on two additional saddles 33, 34- to provide driving means for a secondset of facing thread carriers to produce a V neck anda second set of backing thread carriers are-provided'to cooperate therewith. In order that the second set of facing thread carriers maintains the requisite lead over the. second set of backing thread carriers, the latter are driven by a third chain (not shown) which is driven in asirnilar manner to the backing thread carrier bar driving-chain 18.

The draw lever 30 which reciprocates the rack29 is actuated by cam 35 which carries link 36, the latter moving horizontally along track 37 due to rollers '38 and 39, as described in the aforementioned application.

Various changes and modifications may be made with; out departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is-claimed as new and desired to be secured by Letters Patent, is:

1. In a straight-bar knitting machine; a facing thread carrier for laying a facing thread, a backing thread carrier for layingabackingthread, apair of endless chains operatively connected with said carriers, respectively, for actuation of the latter, a pair of sprockets over which said chains are trained, respectively, a pair of pinions operatively connected Withsaid, sprockets, respectively, gear means operatively connected with both of said pinions, reciprocated'rack means operatively connected with said gear means for reciprocating the latter to thereby reciprocate said thread carriers, and lost-motion means disposed and operativelyconnected intermediate the pinion and the sprocket of said, backing thread carrier, whereby upon actuation of said rack means the sprocket of said backing thread carrier is-actuated only after said facing thread carrier has-travelled'a predetermined distance so that said backing thread carrieris retarded relative to said facing thread carrier.

2. In a machine according to claim 1; said lost-motion means including a dog clutch provided with meshing teeth having clearance therebetweemwhereby upon actuation of said pinions said sprocket of said backing thread carrier is actuated only after said clearance is taken up.

3. In a straight-bar knitting machine; facing thread carrier means for laying a facing thread,v backing thread carrier means for laying a backing thread, a pair of endless band means operatively connected 'with said carrier means, respectively, means for reciprocating said pair of endless band means andthus said carrier means, said reciprocating means including a lost-motion device whereby movement of said endless band means of said backing thread carrier means is initiated only after said endless band means of said facing thread carrier means has moved a predetermined amount.

4. In a machine according to claim 3; said reciprocating means including'a pair of pinion means for said endless .bandmeans, respectively, each of said pinion means driving its respective endless band means, and rack means for driving both said pinion means.

5 In a machineaccording to claim 4; said pinion means of said backing thread carrier means being coaxially arranged with sprocket means, said sprocket means being operatively connected with said endless band means, said lost-motion device being operatively connected between said pinion means of said backing thread carrier means and said sprocket means.

References Cited in the file of this patent UNITED STATES PATENTS 2,241,779 Hartmann. May 13, 1941 2,353,973 Shortland ,July- 18, 1944 2,487,943 Pianta Nov. 15, 1949 

